• Title/Summary/Keyword: Alternative host

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Self-Transmissible IncP R995 Plasmids with Alternative Markers and Utility for Flp/FRT Cloning Strategies

  • Santiago, Clayton P.;Quick, Laura N.;Wilson, James W.
    • Journal of Microbiology and Biotechnology
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    • v.21 no.11
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    • pp.1123-1126
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    • 2011
  • The IncP plasmid R995 has been a useful self-transmissible, broad-host-range vector for a number of applications including the recombinase/conjugation-based cloning of large genomic DNA segments. However, R995 derivatives (or related plasmids) expressing a wide range of different resistance markers and Flp recombinase target sites do not exist in the literature. In addition, documented strategies for applying such plasmids in cloning applications that take advantage of conjugation for the convenient isolation and recovery of constructs are extremely limited. Here, we report a new series of R995 plasmids with alternative markers to increase options for applications in backgrounds already expressing resistance to a particular antibiotic(s). These R995 plasmids have been engineered to contain FRT sites that can be used for recombinase-based cloning. We demonstrate the utility of this approach by cloning 20 kb regions from the Salmonella Typhimurium and Escherichia coli genomes and by cloning DNA from an exogenous plasmid source. To our knowledge, this represents the first systematic engineering of an intact, self-transmissible IncP plasmid with a series of alternative antibiotic markers and FRT sites.

Physiological characteristics of the Large Copper butterfly, Lycaena dispar (Lepidoptera: Lycaenidae)

  • Kim, Seong-Hyun;Hong, Seong-Jin;Lee, Young-Bo;Park, Hae-Chul;Je, Yeon-Ho;Kim, Nam-Jung
    • International Journal of Industrial Entomology and Biomaterials
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    • v.23 no.2
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    • pp.215-221
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    • 2011
  • To establish an indoor-rearing system for the Large Copper butterfly, $Lycaena$ $dispar$ and the Small Copper butterfly, $Lycaena$ $phlaeas$, the effect of temperature, photoperiod and host plants on larval development was investigated. The larvae of $Lycaena$ $dispar$ fed on $Rumex$ $crispus$, whereas the larvae of $Lycaena$ $phlaeas$ ate both $Rumex$ $crispus$ and $Rumex$ $acetosa$. The duration of the larval period of $Lycaena$ $dispar$ was 13.8 days on $R.$ $crispus$ and that, of $Lycaena$ $phlaeas$ was 15.9 days and 15.2 days on $R.$ $acetosa$ and $R.$ $crispus$ respectively. Laboratory experiments show that the Large Copper larvae are able to feed on other $Rumex$ species without harming their overall survival and can utilize these alternative host plants at least as efficiently as their natural host plant. This result suggests that plant chemistry is not responsible for their lack of utilization of the alternative host plants in the wild. Host plant choice by ovipositing females was measured with the two alternative hosts. $Lycaena$ $dispar$ preferred $R.$ $crispus$ to $R.$ $acetosa$, wheareas $Lycaena$ $phlaeas$ preferred $R.$ $acetosa$ to $R.$ $crispus$. Temperature has been proposed as an important determinant of developmental rate, lifespan and mortality in invertebrates. As temperature increased, length of the developmental period gradually decreased. The developmental period of the Large Copper larvae was 11.0 days and 28.5 days at $30^{\circ}C$ and $17.5^{\circ}C$, respectively.

Reaction of Five Non-cereal Grasses to Five Races and Two Host Selective Toxins of Pyrenophora tritici-repentis

  • Ali, Shaukat;Langham, M.A.C.
    • The Plant Pathology Journal
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    • v.31 no.3
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    • pp.245-251
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    • 2015
  • Alternative hosts increase the difficulty of disease management in crops because these alternate hosts provide additional sources of primary inoculum or refuges for diversity in the pathogen gene pool. Agropyron cristatum (crested wheatgrass), Bromus inermis (smooth bromegrass), Pascopyrum smithii (western wheatgrass), Stipa viridula (green needlegrass), and Thinopyrum intermedium (intermediate wheatgrass), commonly identified in range, prairie, verge, and soil reclamation habitats, serve as additional hosts for Pyrenophora tritici-repentis, the cause of tan spot in wheat (Triticum aestivum L.). A. cristatum (five lines), B. inermis (seven lines), P. smithii (four lines), S. viridula (two lines), and T. intermedium (six lines) were tested for their reactions to 30 representative P. tritici-repentis isolates from races 1-5. Plants were grown until the two-three-leaf stage in a greenhouse, inoculated individually with the 30 isolates, held at high humidity for 24 h, and rated after 7 days. All lines developed lesion types 1-2 (resistant) based on a 1-5 rating scale. Also, leaves from an additional plant set were infiltrated with two host selective toxins, Ptr ToxA as a pure preparation and Ptr ToxB as a dilute crude culture filtrate. All lines were insensitive to the toxins. Results indicate that these grass hosts have a limited or nonsignificant role in tan spot epidemiology on wheat in the northern Great Plains. Additionally, the resistant reactions demonstrated by the grass species in this research indicate the presence of resistance genes that can be valuable to wheat breeding programs for improving wheat resistance to P. tritici-repentis.

Recent Progress in Understanding Host Mucosal Response to Avian Coccidiosis and Development of Alternative Strategies to Mitigate the Use of Antibiotics in Poultry Production

  • Lillehoj, Hyun-Soon;Lee, Sung-Hyen;Jang, Seung-Ik;Kim, Duk-Kyung;Lee, Kyung-Woo
    • Korean Journal of Poultry Science
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    • v.38 no.4
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    • pp.275-284
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    • 2011
  • As the world population grows and developing countries become more affluent, the global consumption of meat will increase by more than 50% within the next 10 years. Confronting the increased demand for poultry food products are emerging field diseases, increasing regulatory bans of antimicrobial growth promoters, high-density growth conditions, and waste management. Although biotechnology offers solutions to some of these challenges, basic studies are needed to better understand the complex interaction between the intestinal microbiome, host immunity and the environment. This presentation will focus on emerging strategies to enhance gut immunity and to decrease economic losses due to poultry diseases. This presentation will highlight recent developments in coccidiosis research and provide information on host immunity, immunomodulation, and the latest advances in dietary and nutritional approaches against coccidiosis. Such information will magnify our understanding of host-parasite biology, mucosal immunology, and design of future nutritional interventions and vaccination strategies for coccidiosis.

An Improvement Discussion of Remedy in the Enforcement Mechanism of the International Investment Arbitral Award (국제투자중재판정의 집행에 있어서 구제조치의 개선방안)

  • Hong, Sung-Kyu
    • Journal of Arbitration Studies
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    • v.27 no.1
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    • pp.131-160
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    • 2017
  • When any investment dispute arises, the investor has to exhaust the local remedies available in the host state, and according to the agreement between the parties, the investor is filed to the ICSID arbitral tribunal to seek arbitral awards. At this time, if the arbitral tribunal decides that the investment agreement has been violated, it normally demands the host state to provide financial compensations to the investor for economic loss. According to the rules of the investment agreement, the host state is supposed to fulfill the arbitral awards voluntarily. If it is unwilling to provide financial compensations according to the arbitral awards, however, the investor may ask the domestic court of the host state for the recognition and enforcement of arbitral awards. In addition, if the host state is unwilling to fulfill arbitral awards on account of state immunity, the investor may ask his own country (state of nationality) for diplomatic protection and urge it to demand the fulfillment of arbitral awards. Effectiveness for pecuniary damages, a means to solve problems arising in the enforcement of investment arbitral awards, is found to be rather ineffective. For such cases, this study suggests an alternative to demand either a restitution of property or a corrections of violated measures subject to arbitral awards.

Biological Control Strategy of Uzi Fly in Sericulture

  • Singh, R.N.;Saratchandra, Beera
    • International Journal of Industrial Entomology and Biomaterials
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    • v.6 no.2
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    • pp.125-132
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    • 2003
  • Uzi fly (Exorista bombycis Louis) is one of the major larval endo-parasitoid of silkworm (Bombyx mori). It causes extensive damage to sericulture industry. The application of synthetic organic pesticides has tremendous impact on minimizing pest population but their overuse and frequent misuse and high sensitivity towards the silkworms, has forced the entomologists to search for alternatives to chemical control, which is safe to silkworm, environment and farm workers. Biological control continues to offer exciting possibilities for the control of fly pest population. It is environmentally safe alternative to chemical control and offering a long-term protection. Several potential hymenopteran parasitoids have been screened. Among successful natural enemies, Nesolynx thymus, Trichomalopsis apanteloctena, Trichopria sp., Brachymeria lasus, Pediobius sp., Spalangia sp., Spilomicrus karnatakensis and Dhirhinus sp. are important. It is essential to predict accurately the efficacy of these natural enemies in a new habitat prior to its introduction. The important desirable attributes of these potential parasitoids viz., host searching capacity, specificity, power of increase and fitness and adaptability of the parasitoid in new environment has been recorded. Results of the host parasitoid interaction indicate that the aging of the host function as a factor that influence the host finding efficiency of the parasitoid. It is highly scored with 15-20 hrs old pupa of the host. However, aging of the parasitoid does not significantly affect it. The sex ratio is female biased which is advantageous from biological control point of view, Biological suppression methods involving conservation and utilization of natural enemies have been discussed in detail.

Alternative Therapies with Tacrolimus and Low-Dose Doxycycline for Oral Chronic Graft-versus-Host Disease That Is Resistant to Topical Corticosteroid Medication: Case Report

  • Ju, Hye-Min;Ahn, Yong-Woo;Ok, Soo-Min;Jeong, Sung-Hee
    • Journal of Oral Medicine and Pain
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    • v.43 no.1
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    • pp.16-20
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    • 2018
  • Graft-versus-host disease (GVHD) is frequent complications of hematopoietic stem cell transplantation. In the chronic GVHD (cGVHD), the oral cavity is the most commonly affected region. The clinical manifestations include erythema, ulceration, lichenoid-hyperkeratotic change in oral mucosa, dry mouth, and limitation of mouth opening. The initial treatment strategy of oral cGVHD patients is topical corticosteroid therapy in various formulation. However, corticosteroid resistance appears in some patients. We report a case of a 25-year-old male patient with oral cGVHD, who has resistance to topical corticosteroid medication, treated with 0.03% tacrolimus ointment and low-dose doxycycline. The patient showed subjective and objective improvement without side effect.

Biosynthesis of Chondroitin in Engineered Corynebacterium glutamicum

  • Cheng, Fangyu;Luozhong, Sijin;Yu, Huimin;Guo, Zhigang
    • Journal of Microbiology and Biotechnology
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    • v.29 no.3
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    • pp.392-400
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    • 2019
  • Chondroitin, the precursor of chondroitin sulfate, which is an important polysaccharide, has drawn significant attention due to its applications in many fields. In the present study, a heterologous biosynthesis pathway of chondroitin was designed in a GRAS (generally recognized as safe) strain C. glutamicum. CgkfoC and CgkfoA genes with host codon preference were synthesized and driven by promoter Ptac, which was confirmed as a strong promoter via GFPuv reporter assessment. In a lactate dehydrogenase (ldh) deficient host, intracellular chondroitin titer increased from 0.25 to 0.88 g/l compared with that in a wild-type host. Moreover, precursor enhancement via overexpressing precursor synthesizing gene ugdA further improved chondroitin titers to 1.09 g/l. Chondroitin production reached 1.91 g/l with the engineered strain C. glutamicum ${\Delta}L-CgCAU$ in a 5-L fed-batch fermentation with a single distribution $M_w$ of 186 kDa. This work provides an alternative, safe and novel means of producing chondroitin for industrial applications.

Adaptation of Anisopteromalus calandrae (Hymenoptera: Pteromalidae) to an alternative host, Callosobruchus chinensis (Coleoptera: Bruchidae) (Anisopteromalus calandrae (Hymenoptera: Pteromalidae)의 대체기주 팥구미(Callosobruchus chinensis (L.))에 대한 적응)

  • Kim, Jung;Chun, Yong-Shik;Ryoo, Mun-Il
    • Korean journal of applied entomology
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    • v.34 no.3
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    • pp.278-286
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    • 1995
  • Adaptation of Anisopteromalus calandrae maintained on rice weevil (Sitophilus oryzae) to an alternative host, adzuki bean weevil (Callosobruchus chinensis) was studied. A. calandrae required two generations to adapt to the adzuki been weevil. Through the adaptation, the mean($\pm$SEM) life span of th females became shorter $8.7\pm$1.3 days at the first generation to $6.9\pm$0.6 days at the second generation. Number of eggs laid per female increased from 29.3$\pm$7.7 to $68.2\pm$6.5. Consequently intrinsic rate of natural increase and net reproductive rate were increased. The generation time and population doubling time were decreased. The searching efficiency based on functional and numerical response of A. calandrae to the adzuki bean weevil were similar to each other, but the coefficient of variation decreased with the generation, suggesting that searching efficiency became stable when the parasitoid adapted to adzuki bean weevil. No time lag was required for A. calandrae adapted to the adzuki bean weevil to adapt again to th rice weevil and the searching efficiency of the parasitoid remained on a similar level for the first generation on.

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Population of Rice Stripe Virus-Viruliferous Insect and Natural Weed Host of Rice Stripe Virus.

  • Park, Jin-Woo;Jin, Tae-sung;Shin, Dong-bum;Park, Byung-ryul;Kim, Jin-young;Oh, In-suk;Lee, B. C.;T. H. Noh;S. J. Ko
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • 2003.10a
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    • pp.140.2-141
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    • 2003
  • Among over-wintering small brown planthoppers, population of the rice stripe virus (RSV)-viruliferous insects was surveyed throughout the country in late April of 2003 by using DAS-ELISA. Averaged population of the RSV-viruliferous insects in this year was 2.1%, which was lower than that of last year of 3.7%. However, the insect population in Seoul, Incheon and Kyeonggi areas were relatively high showing 6.7%, 6.2% and 2.6%, respectively. Based on the survey results, it was expected that overall occurrence of RSV on rice could be decreased in this year, except certain areas. Ovarial transmission rate of RSV by the insects on diseased rice samples collected from 10 areas ranged from 22.2% to 77.8%. Among 35 graminous weed species collected from rice fields in Ganghwa and Kimpo in 2002 and 2003, common reed and formosens were found to be infected by RSV. The result indicates that those weeds are potential alternative natural hosts of the RSV Further studies on ecological and pathological impacts of the alternative natural host of RSV are being processed.

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